Surgical treatments for ear, nose and throat (ENT) disorders (e.g. sinusitus) have evolved slowly. In current clinical practice, functional endoscopic sinus surgery (FESS) is used to treat disorders where mucous drainage is impaired and/or chronic infections are present. In FESS, an endoscope is inserted into the nose and, under visualization through the endoscope, the surgeon may remove diseased or hypertrophic soft tissue or bone and may enlarge the ostia of the sinuses to restore normal drainage of the sinuses. FESS procedures can be effective in the treatment of sinusitis and for the removal of tumors, polyps and other aberrant growths from the nose. Other endoscopic intranasal procedures have been used to remove pituitary tumors, to treat Graves disease (i.e., a complication of hyperthyroidism which results in protrusion of the eyes) and to bring about surgical repair of rare conditions, such as cerebrospinal fluid rhinorrhea where cerebrospinal fluid leaks into the nose.
In certain instances, sinus and ENT surgery has been performed with the assistance of electronic navigation devices (i.e., “image-guided FESS”). In typical image guided surgical procedures, integrated anatomical information is supplied through CT-scan images or other anatomical mapping data taken before the operation. Data from a preoperative CT scan or other anatomical mapping procedure is downloaded into a computer and special sensors known as localizers or location sensors are attached to the surgical instruments. Thus, using the computer, the surgeon can ascertain, in three dimensions, the precise position of each location sensor-equipped surgical instrument at any given point in time. This information, coupled with the visual observations made through the standard endoscope, can help the surgeon to carefully position the surgical instruments to avoid creating CSF leaks and to avoid causing damage to nerves or other critical structures.
Although FESS is an accepted therapy for severe sinuses, it has several shortfalls. Often patients complain of the post-operative pain and bleeding associated with the procedure. A significant subset of patients remain symptomatic even after multiple surgeries. Since FESS is considered an option only for the most severe cases (those showing abnormalities under CT scan), a large population of patients exist that either cannot tolerate the prescribed medications or are not considered candidates for surgery. Further, because the methodologies to assess sinus disease are primarily static measurements (e.g., CT, MRI), patients whose symptoms are episodic are often simply offered drug therapy when in fact underlying mechanical factors may play a significant role in their condition. To date, there is no mechanical therapy offered for these patients, and even though they may fail pharmaceutical therapies, no other course of action is indicated. This leaves a large population of patients in need of relief, unwilling or afraid to take steroids, but not sick enough to qualify for surgery.
The need for more minimally invasive treatments of diseased paranasal sinuses has resulted in the proposal of balloon dilation methods and devices. For example, U.S. Pat. No. 2,525,183 (Robison) discloses an inflatable pressure device which can be inserted within the sinus and inflated to restore the sinus passage to normal conditions. Lanza and others have used a Fogarty balloon to dilate nasal sinus passages to enlarge the openings and restore normal mucous drainage, as described by Orlandi et al (2001) and referenced by Lanza (2006).
U.S. Patent Publication No. 2004/0064150 A1 (Becker) and related applications disclose balloon catheters formed of a stiff hypotube to be pushed into a sinus. The balloon catheters have a stiff hypotube with a fixed pre-set angle that enables them to be pushed into the sinus. In at least some procedures wherein it is desired to position the balloon catheter in the ostium of a paranasal sinus, it is necessary to advance the balloon catheter through complicated or tortuous anatomy in order to properly position the balloon catheter within the desired sinus ostium. Also, there is a degree of individual variation in the intranasal and paranasal anatomy of human beings, thus making it difficult to design a stiff-shaft balloon catheter that is optimally shaped for use in all individuals. Indeed, rigid catheters formed of hypotubes that have pre-set angles cannot be easily adjusted by the physician to different shapes to account for individual variations in the anatomy. In view of this, the Becker patent application describes the necessity of having available a set of balloon catheters, each having a particular fixed angle so that the physician can select the appropriate catheter for the patient's anatomy. The requirement to test multiple disposable catheters for fit is likely to be very expensive and impractical. Moreover, if such catheter are disposable items (e.g., not sterilizable and reusable) the need to test and discard a number of catheters before finding one that has the ideal bend angle could be rather expensive. Furthermore, the rigidity of the catheters described by Becker may make access to certain acutely angled ostia difficult in the confined space of the nasal cavity. A further disadvantage of Becker is the inability to verify that the balloon position is in the correct location. In some anatomy where direct visualization is difficult to impossible, for example in the frontal recess, there is a risk of entering and dilating the wrong opening, which at best does not resolve the clinical symptoms and in some cases may lead to severe clinical complications.
Further, balloon dilation of the paranasal sinuses has been proposed using traditionally vascular devices and techniques. For example, European physicians have reported the use of a hydrophilic guidewire and standard PTCA balloon catheter to treat restenosis of surgically created openings in diseased frontal sinuses and stenotic nasal conae. Göttmann, D., Strohm, M., Strecker, E. P., Karlsruhe, D. E., Balloon dilatation of Recurrent Ostial Oclusion of the Frontal Sinus, Abstract No. B-0453, European Congress of Radiology (2001); Strohm, M., Göttmann, D., Treatment of Stenoses of Upper Air Routes by Balloon Dilation, Proceeding of the 83rd Annual Convention of the Association of West German ENT Physicians (1999).
A system of devices utilizing this approach is described in U.S. Pat. Nos. 7,462,175 and 7,500,971. This system includes a guidewire, and a guide catheter to position a balloon catheter into the target paranasal sinus. The balloon is then inflated to dilate the nasal opening. This system provides some advantages over the rigid system described by Becker. The guide wire allows access to sinuses around tortuous anatomy, with the guide catheter providing support for the floppy guide wire and balloon catheter. This system also includes two possible methods of position verification: fluoroscopy, or a guidewire with illumination.
Clinical experience with this system has demonstrated successful access and balloon dilation of sinus passages. However, several disadvantages remain with this approach. The addition of devices such as guide wires and guide catheters to navigate and position the balloon adds significant complexity and cost to the surgical case. As described, this added cost and complexity often prohibits these prior systems to be used in conjunction with standard sinus surgery equipment and techniques, but instead be used as a stand-alone procedure for isolated disease. This factor limits the clinical utility of this prior system, for example it does not allow the concurrent removal of the uncinate process or removal of the ethmoid air cells. In addition, the techniques employed to use these prior systems are not standard to the average ENT surgeon and require extensive training. Use of the fluoroscopy system alone requires extensive and expensive additions to operating room equipment, user training, and in some cases user certification. In addition, as with the Becker system, the guide catheters are shaped with a set angle, so that access to multiple sinuses in one patient may involve the use of several devices, increasing the cost of the procedure still further. Another disadvantage with the method used to place the balloon catheter, requiring the manipulation of a guide catheter and guide wire, is that this method requires at least two hands, and sometimes a third via an assistant, thus the concurrent use of an endoscope for direct visualization, as is standard for current sinus surgical procedures, would require an assistant: further cost and personnel in the operating room.
The structure of these devices also presents disadvantages. Because of the lack of rigidity of the guidewire and guide catheter, it is impossible to precisely locate the tips of these devices in 3-D space. While this is not an issue for vascular procedures where the working space is essentially linear, this is not true for the sinus cavities. Further, the lack of rigidity of the devices also lessens the ability to push the balloon across the tight spaces often encountered in chronic sinusitis patients, which may be obstructed by scar or granulation tissue. Finally, the lack of rigidity precludes the use of image guidance navigation systems for positioning and verifying the location of the balloon.
Recent publications have shown that the uncinate process, which shields the openings of the maxillary and frontal sinus and contribute to their ostia and outflow tracts, must be removed in order to allow the maximal drainage of these sinuses. Without removing the uncinate process and diseased tissue of the ethmoid air cells, the potential for surgical failure and need for revision dramatically increases. Additionally, maintenance of patency of the maxillary, frontal and sphenoid sinus can not be assured by purely balloon dilating the opening, and may require stenting the dilated sinus with an expandable stent to assure patency. The stent should preferably be absorbable to eliminate the risk and cost of removing the stent after healing has occurred.
Prior systems, based on cardiovascular technology, utilize the natural cannula created by the veins to assist in guiding the device. Such systems may use guide catheters and guide wires for delivery and positioning. In addition, these systems can require fluoroscopy and/or illumination devices for navigation and placement verification.
Prior devices, systems and methods have not been optimized for minimally invasive treatment of sinusitis, mucocysts, tumors, infections, hearing disorders, fractures, choanal atresia or other conditions of the paranasal sinuses, Eustachian tubes, Lachrymal ducts and other ear, nose, throat or mouth structures in which the atraumatic dilation and maintance of these structures is desirable. Non-articulating instruments are not capable of navigating the tortuous pathway to some of these structures. Guidewire and guide catheter access to these structures may not be possible without risk of trauma to the anatomy, or in some cases may not be possible at all. Systems are needed which can provide balloon dilation devices utilizing hand-held, articulating insertion devices that enable accurate and rapid access to these anatomic structures, and allow balloon dilation as an adjunct to surgical procedures on these structures. For example, balloon dilation of sinus ostia will allow removal of diseased tissue such as tumors or cysts without additional surgical modification. Balloons can also be used to treat orbital floor fractures by providing stability to the orbital floor via the maxillary ostia without the need for rigid fixation. In addition to dilation of the sinus ostia, balloons can be used to dilate other stenotic regions such as the nasal choana to relieve nasal obstruction due to stenosis, in the Eustachian tube to relieve Eustachian tube obstruction and in the lacrimal duct to relieve epiphora.
There exists a need for a balloon dilation system which can be delivered and positioned using surgical instrumentation and techniques currently employed by ENT surgeons, and which may be articulated by the user to aid in access and positioning in confined spaces, and to account for the variety of anatomy encountered during treatment of a single patient, as well as the variety of anatomy from patient to patient. There furthermore exists a need for a balloon delivery system which does not require the use of guide catheters and/or guide wires, with associated procedure time and cost, as well as pre-requisite training and equipment. In addition, there exists a need for a balloon dilation system which can be used in conjunction with image-guidance navigation systems, and which do not require the use of position verification methods and equipment not standard to the average ENT surgeon such as fluoroscopy or illumination. Additionally, there exists a need for a system which can deliver a stent to a dilated sinus. Some or all of these needs are met with the invention provided herein.